Trackers are used in peer-to-peer (P2P) networks for provider discovery, that is, mapping resources to potential providers. Centralized trackers, e.g., as in the original BitTorrent protocol, do not benefit from P2P properties, such as no single point of failure, scalability, and load balancing. Decentralized mechanisms have thus been proposed, based on distributed hash tables (DHTs) and gossiping, such as BitTorrent's Peer Exchange (PEX). While DHT-based trackers suffer from load balancing problems, gossip-based ones cannot deliver new mappings quickly. This paper presents B-Tracker, a fully-distributed, pull-based tracker. B-Tracker extends DHT functionality by distributing the tracker load among all providers in a swarm. Bloom filters are used to avoid redundant mappings to be transmitted. This results in the important properties of load balancing and scalability, while adding the ability for peers to fetch new mappings instantly. B-Tracker shows, through simulations, improved load balancing and better efficiency when compared to pure DHTs and PEX.
[1]
Keith W. Ross,et al.
Understanding Peer Exchange in BitTorrent Systems
,
2010,
2010 IEEE Tenth International Conference on Peer-to-Peer Computing (P2P).
[2]
Shahar Boneh,et al.
Asymptotics for the random coupon collector problem
,
1998
.
[3]
Burton H. Bloom,et al.
Space/time trade-offs in hash coding with allowable errors
,
1970,
CACM.
[4]
Dan S. Wallach,et al.
An Analysis of BitTorrent’s Two Kademlia-Based DHTs
,
2007
.
[5]
Maximilian Michel,et al.
Can P2P-Users Benefit from Locality-Awareness?
,
2010,
2010 IEEE Tenth International Conference on Peer-to-Peer Computing (P2P).
[6]
Taoufik En-Najjary,et al.
A global view of kad
,
2007,
IMC '07.
[7]
B. Cohen,et al.
Incentives Build Robustness in Bit-Torrent
,
2003
.
[8]
Chadi Barakat,et al.
Understanding the Properties of the BitTorrent Overlay
,
2007,
ArXiv.